Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f755b0c78b4d872…

MALICIOUS

PDF

74.0 KB Created: 2021-09-18 05:02:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ec27170e41130a85f3248eab264cf426 SHA-1: 7d99a4ff1f6ab024d4f7a720f6f9755e5e663eaa SHA-256: 5f755b0c78b4d872d406709171a366f468276e3e7fbb7981533be46347c02656
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links pointing to compromised websites and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of external URI heuristics and compromised CMS upload links reinforces the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://smidgel.ru/uplcv?utm_term=imo+hd+video+call PDF link annotation
    • https://www.dooleysnaturalgas.com/ckfinder/userfiles/files/36579518456.pdfIn PDF document text
    • https://glaze-metalart.com/upload/files/bazizojakimorukaworiku.pdfIn PDF document text
    • https://sergiomauri.com/images/file/25580738854.pdfIn PDF document text
    • http://opt-russtd.ru/data_center/upload_pictures/file/zisaludobewawisidujolepi.pdfIn PDF document text
    • http://sahrugs.com/userfiles/file/82041279720.pdfIn PDF document text
    • http://dietgame.net/admin/fckeditor/data/file/20210908123829.pdfIn PDF document text
    • http://sportingclubalbinia.eu/userfiles/files/24195964026.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e015492829---bogujuzi.pdfIn PDF document text
    • https://yourownadviser.com/ckfinder/userfiles/files/ludaxuwiberugutovo.pdfIn PDF document text
    • http://studiogiovannone.com/userfiles/files/dofujus.pdfIn PDF document text
    • http://9jamail.com/FCKeditor/editor/filemanager/connectors/userfiles/file/metilomolo.pdfIn PDF document text
    • http://ty-int.com/files/files/pedazi.pdfIn PDF document text
    • http://seibyou-koujien.com/files/files/43018287131.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/k7lgmreotijvm02nj8tb1qbdut/40958548973.pdfIn PDF document text
    • http://kaies.cn/upfiles/210901144158472279f49vuz.pdfIn PDF document text
    • https://kibledergisi.net/resimler/files/37151271325.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130a768e33be---jasawiput.pdfIn PDF document text
    • http://solentpodiatry.com/jackvl940/web/content/images_uploaded/file/kunikuxopune.pdfIn PDF document text
    • http://huiking.cn/uploads/file/082026106841.pdfIn PDF document text
    • http://123dvere.sk/files/file/27564163639.pdfIn PDF document text
    • http://nurugelexport.com/ckfinder/userfiles/files/fixakiserubikadizunesurun.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b8ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d0be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0BE 19556 bytes
SHA-256: b7c6edab3f7fd0db825d14ab0f06e1e4ac8b8a8166d133054ef1969c50dc173a
font_02_sfnt_off000103fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103FA 10180 bytes
SHA-256: 1eddad777113e8a93b9ca6a427d4c7c2bf31fff5b621fda91615b7de052d4380